1. Field of the Invention
The present invention relates to an electronic apparatus such as a computer, having a compact construction, such as a laptop personal computer or a notebook personal computer in which a display portion is opened and closed.
2. Description of the Related Art
In recent years, CPUs have attained high performance; keyboards have had a large number of keys installed thereon with a high density; memory has become of large capacity; disk devices have become compact but with large capacity; and display devices comprising liquid crystals have become thin. Because of this tendency, an increasing number of compact personal computers have been manufactured. In particular, an increasing number of laptop personal computers or notebook personal computers have been manufactured in which a display section thereof is accommodated in a display casing while a main body section is accommodated in a main body casing. When this type of computer is used, the display section is pivoted toward a position in which an operator can view the display screen of the display section. When the computer is not being used, the display section is pivoted to close the display section like a cover. Therefore, the computer is handy to carry. This tendency will be also seen in an electronic apparatus such as a large scale computer including a work station.
Although the computer has become more and more compact, the size of the display screen and that of the keyboard thereof cannot be made smaller than a certain size in view of operational performance requirements of the computer. It is important for the display screen to be large, clear, and precise so that the computer is acceptable to an operator. Accordingly, in the compact electronic apparatus manufactured in recent years, the ratio of the area of the display screen to that of the main body casing is approximately 1:1. In such an electronic apparatus, the pivotal axis of the display casing accommodating the display section is disposed in the vicinity of the rear end of the main body casing.
A signal for driving the display means is transmitted from the circuit of the main body of the computer to the display means thereof at a high speed and is liable to be influenced by noises. In order to overcome this problem, a cable to connect the display means of the computer with the main body thereof has increasingly become sheet-shaped and flexible to perform a favorable grounding and conform to the arrangement requirements regarding signal lines. In order to movably wire the flexible cable between the display casing and the main body casing, it is necessary to form a large space in the vicinity of the pivotal axis of the display casing. In the above-described construction of the electronic apparatus, it is very difficult to install the pivotal axis of the display casing in the vicinity of the rear end of the main body casing.
An example of the construction of the conventional electronic apparatus is described below with reference to FIGS. 5 through 8.
FIG. 5 is a perspective view showing the configuration of the conventional electronic apparatus. FIG. 6 is a sectional side elevation showing the vicinity of a hinge unit of the conventional electronic apparatus. FIGS. 7 and 8 are perspective views showing the configuration of parts, of the conventional electronic apparatus, disposed in the vicinity of the hinge unit.
Referring to FIGS. 5 through 8, the electronic apparatus comprises a keyboard 126; a display means 114; a main body circuit 125 for controlling a signal to be transmitted to the display means 114 according to data inputted via the keyboard 126; a main body casing 121 accommodating the keyboard 126 and the circuit 125; a hinge unit 104; and a display casing 111, accommodating the display means 114, supported by the hinge unit 104 via a hinge portion 111c disposed in the vicinity of the rear end thereof so that the display means 114 is rotatable on the main body casing 121. The display casing 111 can be pivoted more than 90.degree. from a closed state (state shown in FIG. 6b) to an open state (state shown in FIG. 6a.) In the closed state, the display casing 111 is closed like a cover so as to be portable. In the open state, an operator views the display screen of the display casing 111. Image signals and electrical power are supplied from the circuit 125 to the display means 114 via a long flexible cable 101 on which a wiring pattern has been printed. As shown in FIG. 7, the flexible cable 101 passes through a slit 111b of the display casing 111 and an opening 121a of the main body casing 121 shown in FIG. 8, thus extending from the display casing 111 to the main body casing 121. In pivoting the display casing 111 from the open state of FIG. 6a to the closed state of FIG. 6b, most of the hinge portion 111c can be seen from outside. Therefore, the exit, namely, the slit 111b of the display casing 111 through which the flexible cable 101 passes is necessarily small as shown in FIG. 8 while it is necessary to make the opening 121a of the main body casing 121 larger than the slit 111b as shown in FIG. 8 in correspondence with the flexure range of the flexible cable 101 which flexibly moves in the space between the display casing 111 and the main body casing 121.
An example of a method of manufacturing the conventional electronic apparatus is described below with reference to FIG. 9.
First, as shown by an arrow 1A, the circuit 125 and the hinge unit 104 are accommodated in the main body casing 121. A rear cover 112 is fixed to one end 104a of the hinge unit 104 projecting from the main body casing 121 with the rear cover 112 standing upright. Then, as shown by an arrow 1B, the display means 114 connected with one end of the flexible cable 101 is fixed to the rear cover 112, and the other end thereof is then inserted through the opening 121a of the main body casing 121 to connect the flexible cable 101 with the circuit 125 as shown by an arrow 1C. Finally, as shown by an arrow 1D, a front cover 113 is installed on the rear cover 112. The rear cover 112 and the front cover 113 compose the display casing 111.
In the electronic apparatus having the abovedescribed construction, however, it is necessary to provide an upper cover 12lb in the rear of the main body casing 121 so that the opening 121a of the main body casing 121 and the flexible cable 101 cannot be seen from outside. Consequently, the apparatus is large in depth. In addition, the flexible cable 101 is flexed by large amount in the limited space between the display casing 111 and the circuit 125 in correspondence with the rotation of the display casing 111 while the rigidity of the flexible cable 101 prevents the display casing 111 from smoothly pivoting. Furthermore, the flexible cable 101 in the vicinity of the circuit 125 is required to be bent significantly at a small radius of curvature. Therefore, the flexible cable 101 is unreliable in its motion.
In addition, if the opening 111b of the display casing 111 is enlarged and the opening 121a of the main body casing 121 is reduced to solve the above-described problems, it is necessary to provide the electronic apparatus with a shutter or the like which moves synchronously with the pivotal motion of the display casing 111 so as to cover the opening 111b of the display casing 111. As a result, the construction of the apparatus becomes complicated.
Further, in the above-described manufacturing method, the display casing 111 cannot be removed from the main body casing 121 because the display casing 111 is not held together with the main body casing 121. Therefore, it is necessary to disassemble the display casing 111 each time the display means 114 requires maintenance. Moreover, it is inconvenient that the display casing 111 must be fixed to the main body casing 121 with the former standing upright. That is, it takes time and labor to locate the display casing 111 in position on the main body casing 121 with the former in the closed state.